Pneumatic-despatch-tube system.



,P. H. WOLEVER. PNEUMATIC DESPATOH TUBE SYSTEM.

APPLIOATION FILED AUG. 10, 1908.

Patentd Feb. 7, 1911.

; z sums-sum 1.

7H5 Nonms PETERS 00.. WASHINGTON, n. c.

, P. H. WOLEVER. PNEUMATIC DESPATCH TUBESYSTBM. v APPLIOATION I'ILED AUG.10, 1908.

2 SHEETS-SHEET 2.

WTTEE %TATE% PATENT @FFTQEE.

FRANKLIN H. WOLEVER, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, 'IO ROSIE FEIST, OF CHICAGO, ILLINOIS.

PNEUMATIC-DESPATCH-TUBE SYSTEM.

Specification of Letters Patent.

Patented Feb. "3, 1911.

Application filed August 10, 1908. Serial No. 447,665.

To all whom it may concern:

Be it known that I, FRANKLIN H, VVoLE- VER, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Pneumatic- Despatch-Tube Systems; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in pneumatic despatch tube systems and refers more specifically to means for economizing the power used in operating the system.

The invention consists in the matters here- 'inafter set forth and more particularly pointed out in the appended claims.

In the drawings: Figure l is a diagram matic view with parts broken away of a portion of a despatch tube system equipped with my improvements. Fig. 2 is a horizontal view, partially in elevation and partially in section, of the cashiers sending terminal. Fig. 3 is a cross section taken on line 3-3 of Fig. 2. Fig. 4 is a cross section taken on line 4E4t of Fig. 2. Fig. 5 is a cross section taken on said line 4% of Fig. 2, with parts shown in changed positions. Fig. 6 is a cross section taken on line 66 of Fig. 2. Fig. 7 is a side elevation of a modified form of cashiers sending terminal. Fig. 8 is a cross section taken on line S-8 of Fig. 7. Fig. 9 is a detail of a relief valve in the eX- exhaust pipe connecting the main vacuum trunk line of the system with one of the loops extending between the cashiers station and a salesmans station.

As shown in the drawings, 10 designates the cashiers sending tube line and 11 the salesnians sending or return tube.

12 designates as a whole a combined receiving and delivery terminal located at the salesmans station 13, arranged to deliver a cartridge downwardly therefrom to the salesmans desk. Said terminal is of familiar form and embraces a sending gate 14 through which cartridges are delivered to the salesmans sending tube, and an automatically closing gate 15 which closes an opening in said terminal through which cartridges are delivered from the terminal. The terminal 12 is arranged to afiord comproper direction to transmit the cartridges therethrough by connection of the loop at one point with a vacuum inducing means. The sending and delivery terminals of said tubes are normally closed and the system is sealed during periods of disuse.

l8 designates, as a whole, the cashiers sending terminal located at the cashiers desk 19, and 20 designates the cashiers delivery terminal located at said desk and beneath the down turned end of the salesmans sending tube. The end of the salesmans tube above the delivery terminal 20 is equipped with an automatically closing, downwardly opening gate 21 which opens to permit cartridges to be delivered from the salesmans tube to said delivery terminal.

24 designates a pipe which is connected at one end with the delivery end of the cashiers sending tube and at its other end with a vacuum main or trunk 25.

A complete system of this character usu ally embraces a plurality of loops extending from a number of salesmens stations to a single cashiers station, each loop communicating with the vacuum main by a pipe 24. Air at atmospheric pressure is admitted to the loop at the cashiers sending terminal and is withdrawn from the loop through the pipe 24, whereby the air moves in one direction in one tube and in the opposite direction in the other tube. My invention relates to improvements in means for admitting air to the despatch tube arranged to automatically admit air to the tube when a cartridge is inserted or introduced therein and to draw a supply of air as long as a cartridge is traveling through the tube, and to automatically cut cit the supply of air upon the discharge of a cartridge from the system. The despatch tube system is thus sealed during periods of disuse of the system so as .to thereby economize the power required to keep in motion a column of air in the tube to propel cartridges therethrough. The invention relates also to improvements in automatically operated check valves for admitting air to the system and to improve ments in sending terminals through which cartridges are admitted to the system. The

mechanism for thus controlling the admission of air to the system to carry the cartridges therethrough and to shut off the entrance of air to the system when a cart-ridge has been delivered to its station is shown as associated with the cashiers sending terminal and also with the salesmans sending terminal, one or both of which may be employed depending upon the length of the tube and other conditions. The air inlet device at the cashiers sending station is shown being made a structural part of the cashiers sending terminal which practice may advantageously be followed, and may also be varied.

The cashiers terminal embraces a tube section 30, which is jointed to the receiving end of the cashiers sending tube, and an upwardly opening trough-like receiving mouth 31 arranged axially in line therewith, in which the cartridges are laid horizontally to be delivered to the tube section 30.

33 designates a movable valve or gate that is adapted to extend across the bore of the tube section 30 to shut off the admission of air to the system at this point, and to be moved out of line with said section to admit a cartridge to the terminal. The said valve or gate, as herein shown, consists of a flat disk which swings in the direct-ion of its plane toward and from its closed position. The tube section is slitted at its top and at one side to receive said valve and is formed at its unslitted portion with a curved seat groove to receive the marginal part of the valve disk, which latter is shown as made circular in its part within the tube section. Guide wings 35, 35 rise from the tube in line with the slit therein to guide the valve in its swinging movement. The said valve is fixed at one side of the tube section to a rock-shaft 37 which is parallel with the axis of said section and is mounted in lugs 38, 39 extending laterally from the tube. The said valve is herein shown as fixed to the rock-shaft 37 between washers 40, 4O fixed to the shaft, the outer end of the valve being clamped between said washers. The valve fits closely between the guide wings and in the slit of the tube section which receives the same to prevent the leakage of air past the same into the system. It may be made of, or faced with, leather or other suitable material.

The valve is held normally in its closed position across the tube section 30 by means of a torsional spring 42 which surrounds the rock-shaft 37 and is attached at one end to the shaft and provided at its other end with a lateral extension 43 which engages a part stationary with said lugs 38, 39, consisting, as herein shown, of a web 44 made integral with said lugs. The rock-shaft 37 is provided with a crank arm 45 by which the valve may be opened against the action of said spring. hen the valve is thus opened the tube section 30 of the receiving terminal is unobstructed to permit the free passage of a cartridge thereinto.

Means are provided for locking the valve open until the cartridge passes fully into the terminal, so constructed as to automatically release the valve as soon as the cartridge has passed the valve. The means herein shown for effecting this result is made as follows: The rock-shaft is provided on its end remote from the crank arm with a cam disk 50 having at one side thereof an abrupt tooth or projection 51 which is approached from the concentric portion of the disks periphery bya peripheral cam surface 52. 54 designates a horizontally swinging trigger lever which is locted at one side of the tube section and is pivoted between its ends on a stud 55 projecting laterally from the said section. The forward end of said lever is pressed in contact with the periphery of the locking cam 50 by means of a suitably applied spring 56, herein shown as consisting of a U-shaped leaf spring that is inter posed'between the adjacent lateral side of the tube section 30 and the inner face of the said lever. Thus said spring normally holds the trigger lever engaged with said cam, and when said cam is turned in the direction indicated by arrow in Fig. 4, which occurs when the rock-shaft is rocked to open the valve 33, the forward end of the lever swings behind the tooth or projection 51 of said locking cam and locks said rock-shaft in position to hold the valve open. The said trigger is acted upon by the cartridge as it passes through the tube section 30 to release the same from said locking cam. As herein shown, the rear end 58 of the trigger lever extends through an opening 59 in the adjacent side of the tube section into the path of a cartridge passing through said section. The inwardly projected end 58 of said trigger lever 54 is located at such distance from the valve 33, relatively to the length of a cartridge, that the cartridge will have fully passed said valve before it engages said trigger lever. Upon engagement of the cartridge with the end 58 of the said trigger lever, said lever is swung on its pivot to release the same from the tooth or projection 51 of the locking cam, whereupon the spring 42 acts to automatically swing the valve or gate 33 in its closed position. The said trigger lever is inclosed in a casing 60 which prevents the leakage of air into the despatch tube through the opening 58. As herein shown, the lug 39 constitutes one end of said casing.

Means are provided for supplying air to the system behind the cartridge, after the closing of a sending gate, for a sufficient length of time to insure the delivery of the cartridge to its destination. In order to effect this result I provide a valve which opens upon the insertion of a cartridge into the tube and which remains open under the usual working pressure of the system, or at a time when a cartridge is being transmitted through the despatch tube, and which is automatically closed by atmospheric pressure acting against the same after the cartridge has been discharged from the system, thus sealing the system. One of the air admission valves herein shown constitutes part of, or is associated with, the cashiers sending terminal and is made as follows: The tube section 30 of said sending terminal is provided at its lower side with an opening 65 which is inclosed by a short, downwardly extending branch (36 joined to the said tube section. (37 designates a valve disk which has a rising and falling movement and adapted when in its uppermost position to close the opening or said branch 66. The said valve disk 67 is fixed to the upper end of a vertically reciprocating valve stem (38 that has guiding engagement with a tube 69 which is fixed to the lower horizontal member 70 of a. yoke 71 attached to and suspended from the branch 66. As herein shown, the guide tube 69 is exterior-1y screw-threaded for scre .v-threaded engagement with a part 73 carried by the horizontal member of said yoke to afford vertical adjustment of the valve. The valve 67 and its stem may be suitably weighted so that it will close only at a predetermined difference of pressure on the upper and lower sides thereof. As herein shown, the said valve stem is screwthreaded at its lower end and carries one or more nuts T l which may provide the weight required. A suitably applied spring may also answer the purpose of normally holding the valve open. The valve 67 is thus adjustee, relatively to the normal working pressure of the system, and will not close under the influence of the ordinary working pressure of the system. That is, when a cartridge is passing through the despatch tube, the valve rema' is open to admit air to the tube behind the cartridge after the sending gate is closed and until the car tridge is delivered to its proper destination. After the cartridge has been discharged from the system, however, velocity of the moving column of air is increased and its pressure is decreased to such extent that atmospheric pressure acting on the lower side of the valve will close the latter, thus sealing the part of the system or loop which the valve controls. Thereafter, and until another cartridge is delivered to the system at one of the stations, the air in the idle loop is dead or practically stationary so that power not required to keep in motion a current of air in the idle or empty loop.

The operation of a system embodying my improvements may be briefly stated as follows: VVh'en a cartridge is to be admitted to the salesmans sending terminal the sending gate 33 is opened through the medium of the crank arm t5 of the rock-shaft 37. The said sending gate is locked in its open position by the trigger lever 54 and the locking cam 50, and the gate is closed by the action of the spring 42 when the cartridge passes into engagement with the inner end of the trigger lever in a manner to release the lever from the locking cam. The inrush of air to the despatch tube, which occurs upon the opening of the gate 33, lowers the pressure in the tube to such extent that the check valve 67 drops from its seat at the end of the branch 71 whereby air is admitted to the tube through the valve opening 65 behind the cartridge after the cartridge passes said opening. Air is admitted through said opening to the despatch tube to propel the cartridge to its intended destination, and so long as the cartridge remains in the tube, and

when the cartridge is discharged from the terminal 12 at the salesmans station the velocity of the air in the tube is increased and its pressure is decreased to such extent that atmospheric pressure acting against the lower side of the check valve 67 has the effect to close said valve and thereby seal the tube until another cartridge is delivered thereto. Likewise, upon delivery of a cartridge to the sending terminal 12 at the salesmans station, the opening of the sending gate 14 and the iii-rush of air to the tube has the effect of increasing the pressure in the loop or tube, whereby the check-valve 67 is opened to admit air to the tube behind the car tridge. Said check valve remains open and air is supplied to the tube until the cartridge is discharged from the tube to the terminal 20 at the cashiers station, whereupon the valve is closed to seal the tube or loop. Thus it will be seen thatthe admission of air to the tube through said check valve to transmit a cartridge through the tube is controlled wholly by the pressure within the despatch tube, said tube being opened to admit air thereto upon the insertion of a cartridge into the tube, and the tube is automatically closed and sealed upon the discharge of a cartridge from the tube. I am,. therefore, enabled to accurately admit the required volume of air to the tube to transmit a cartridge therethrough without the employment of a timing device and to effect the transmission and delivery of the cartridge regardless of variations of the load and speed of the cartridge or variations of the power. In other words, the mechanism herein shown automatically times the transmission and delivery of the cartridge independently of the load and speed of the cartridge and of variations of power, the discharge of the cartridge from the system absolutely controlling the admission of the propelling air. It will be observed that the opening controlled by the check valve has the full capacity of the tube so as to admit the required volume of air to the tube without restriction, and that the adjustment provided for the valve, including the adjusting sleeve 69 and the means for weighing or otherwise restraining the closing movement of the valve, enables me to accurately adjust the valve to different lengths of transit tubes. The valve itself automatically times itself to varying loads and like conditions.

In Fig. 7 I have shown a modified form of the sending terminal 7 5. The terminal shown in Fig. 7 is provided with a flaring mouth 76 which is closed by a gate 77 that is pivoted at the upper side of the mouth on a pivot pin 78 carried by a lug 79 made integral with the terminal fitting, as herein shown. The said gate is provided with. a finger piece 80 by which it may be opened. The gate, being hinged at its upper side, may be closed by gravity or said closing movement may be assisted by the aid of a suitably applied spring, if desired. The arrangement of the terminal is such that the gate does not fully close when released, but engages a yielding stop which operates to hold the gate partially open so long as a cartridge is in the despatch tube. Said gate is closed by atmospheric pressure act ing on the outer side thereof when the pressure is reduced in the tube, due to the diseharge of a cartridge therefrom. The yield ing stop herein shown is made as follows: designates a pin that is arranged horizontally beneath the mouth of the terminal and is mounted in a horizontal sleeve that is fixed to a lug 87 depending from said terminal 75. The said pin is provided with a head 88 against which the lower side of the gate strikes when swung to its closing position. The pin is held normally projected for engagement of the head thereof with said gate to hold the latter in a. partially open position by means of a spiral expansively acting spring 90 which surrounds said pin and is interposed ietween the head 88 and the head 86. A suitable shoulder, as the nuts 91, are carried by the ends of the said stop pin and engage the rear end of the sleeve to limit the forward movement of the stop pin. In the operation of a system in cluding this type of terminal, the gate 77 is opened to the upper dotted line position to admit a cartridge to the terminal. Thereafter the gate is released and it swings against the stop pin to the position indicated by the lower dotted lines. In this position the gate is held open sulliciently to admit air to the tube behind the cartridge to effect the transit of the cartridge therethrough and its delivery therefrom. As soon as the cartridge has reached its destination and has been discharged from the tube the pressure in the tube is lowered and the superior atm0spheric pressure acting against the outer side of the gate 77 acts to completely close the gate against the action of the spring 90 and seal the system at this point.

The salesmans despatch or transit tubes may, if desired, be provided at the sales mans stations with sending gates of the types hereinbefore described having means for automatically controlling them by the transit through or discharge of a cartridge from the despatch tube.

In despatch tube lines of considerable length I provide an air inlet valve adjacent to the salesmans sending terminal in order that inlet of air to the tube behind the cartridge may be etl ected with greater despatch when a cartridge is inserted into the tube at the salesmans station, and also to avoid the effect of frictional loss in the tube, which in a long line, may tend to close a single inlet valve. Thus the salesmans sending tube is shown in l as provided with a lateral inlet valve opening 66 closed by a check valve (37 like the valve 67 heretofore described.

I have provided a manually operable device for releasing the valve 33 in the event that it should be opened and a cartridge not inserted into the terminal. The releasing device which I have shown consists of a plunger 92 which extends through a sleeve 93 fixed in the side wall of the casing (50, the plunger being arranged to engage the spring pressed end of the trigger lever to swing it out of engagement with the cam tooth 51. A spring t holds said plunger retracted while permitting said plunger to be yieldingly pressed toward said trigger lever.

In a despatch tube system of the type herein shown the main vacuum trunk 25 may be connected with a large number of loops, each having at each end a sending and delivery terminal. In such systems the power plant and pumping mechanism are arranged to adapt themselves to the expected demands of the system, there being a suitable governor mechanism for this purpose, as is usual. Tn the ordinary or normal use of such a system having a large number of loops it is not likely all of the loops connected with the vacuum trunk line will either be in operation or out of use at the same movement. Therefore, there will usually be a. fairly constant demand for power. In order to provide against the disuse or inactivity f all or nearly all parts of the system atany given time when the power plant is in operation I may provide a relief valve 95 in each of the pipes 24: between each operating loop of the system and the vacuum trunlr line 25, so arranged as to admit air to said loop in case of an abnormal tension of the air, due to a relatively large number of inactive loops or sets of tubes. The use of such a relief valve prevents too great an attenuation of the air and great stress on the power plant.

The relief valve which is shown in Fig. 9 comprises a branch 97 extending laterally from the pipe 24 and opening at its inner end into the said pipe and at its outer end to the atmosphere. The said branch is adapted to be closed at its inner end by a valve 98 which is attached to a valve stem or rod 99 extending outwardly through a suitable guide opening in a winged guide 100 located and fixed in the branch 97. The valve is normally held to its seat by means of a spring 101, herein shown as a spiral expansively acting spring, which surrounds the stem 99 and is interposed between the guide 100 and a nut or other suitable shoulder 102 at the outer end of the valve stem. Upon a predetermined decrease of pressure in the system, due to the causes mentioned, said valve will be opened and permit the leakage of air into the system to relieve the low pressure and avoid unnecessary stress on the power plant.

I claim as my invention 1. In a pneumatic despatch tube system, the combination with adespatch tube adapted for connection at one end with vacuum producing means and provided at its other end with a sending terminal closed by a gate, of an unobstructed branch tube connected with said terminal at a point inside the gate and affording an unrestricted passage for air to the despatch tube, and formed at its lower edge to provide an annular valve seat for engagement with a valve and a fiat disk valve the upper fiat face of which is adapted for engagement with said seat for closing the open end of said branch tube, said valve being supported by means located below said branch tube, and adapted to be opened by gravity when the terminal gate is opened to insert a cartridge into the terminal and to be closed by atmospheric pressure upon the discharge of a cartridge from the despatch tube.

2. In a pneumatic despatch tube system, the combination with a normally sealed despatch tube, means for exhausting air from the tube, and a sending terminal through which cartridges are inserted into the tube, of a valve device between the terminal and the discharge end of the tube for admitting air to the tube behind a cartridge to propel the same through the tube, comprising a branch communicating with the tube and opening to the atmosphere,. a check valve adapted to close said branch, said valve being subjected at one side to the pressure in the tube and at its other side to atmospheric pressure and arranged to be directly acted upon by variations of pressure on the opposite sides thereof to open and close the same, and means for adjusting said valve toward and from said branch.

3. In a pneumatic despatch tube system, the combination with a despatch tube adapted for connection at one end with vacuum producing means and provided at its other end with a sending terminal closed by a gate, of an unobstructed branch tube connected wit-l1 the terminal at a point inside the gate and afiording an unrestricted passage for air to the despatch tube, a flat disk valve for closing the open end of the branch tube, a stem extending downwardly from said valve, a support for said disk valve embracing a guide sleeve arranged axially below said branch tube, and means for adj usting said sleeve toward and from the open end of the branch tube.

4. In a pneumatic despatch tube system, the combination with a pair of normally closed despatch tubes extending between and connecting two stations and having their receiving and delivery terminals at respective opposite stations, a connection between said tubes at one station and a vacuum pipe connected with the delivery terminal at the other station, of air inlet valves connected one with each of the sending terminals, said valves being normally closed and arranged to admit air to the tubes behind the cartridges upon the insertion of the cartridge into the despatch tube, the valves being subjected at their inner sides to the pressure in the tubes and at their outer sides to atmospheric pressures and arranged to be directly acted upon by variations of pressure on opposite sides thereof to open and close the same.

5. In a pneumatic despatch tube system, the combination with a despatch tube and an exhaust pipe connected with one end of the tube for exhausting air therefrom, of a re ceiving terminal at the other end of the tube provided with a gate for closing the same and arranged to be opened to admit a cartridge to the terminal, means tending to urge said gate to its closing position, means for locking the gate in its open position, means located within the receiving terminal at a point just inside of said gate for releasing the locking means to permit the gate to be returned to closing position, and a valvecontrolled air inlet passage for supplying air to the tube behind the cartridge after said gate is closed.

6. In a pneumatic despatch tube system, the combination with a despatch tube, and an exhaust pipe connected with one end thereof for exhausting air therefrom, of a receiving terminal through which cartridges are admitted to the tube comprising a gate which normally closes the terminal, said gate comprising a flat plate or disk which swings in its plane and the tube being slotted to receive the valve, a rock-shaft to which said valve is fixed, a spring acting on the rock-shaft to normally hold the gate in its closed position, means acting on the rockshaft for locking the gate in its open position against the action of the spring, and means controlled by the passage of a cartridge through the terminal for releasin said locking means.

7. In a pneumatic despatch ,tube system, the combination with a despatch tube, and an exhaust pipe connected with one end thereof for exhausting air therefrom, of a receiving terminal through which cartridges are admitted to the tube comprising a gate which normally closes the terminal, a rockshaft to which said gate is fixed, a spring acting on the rock-shaft to normally hold the gate in its closed position, a locking projection on said. rock-shaft, and a springpressed trigger lever adapted to engage said locking projection to lock the gate in its open position, one end of said lever extending into the terminal and into the path of the cartridges.

8. In a pneumatic despatch tube system, the combination with a despatch tube, and an exhaust pipe connected with one end thereof for exhausting air therefrom, of a receiving terminal through which cartridges are admitted to the tube comprising a gate which normally closes the terminal, a rocl: shaft to which said valve is fixed,-a spring acting on the rockshaft to normally hold the gate in its closed position, means acting on the rock-shaft for locking the gate in its open position against the action of the spring, a trigger in the terminal controlled by the passage of a cartridge through the terminal for releasing said locking means, and a manually operative device for releasing said locking means.

In testimony, that I claim the foregoing as my invention I aflix my signature in the presence of two witnesses, this th day of August A. D. 1908.

FRANKLIN H. YVOLEVER.

lVitnesses VILLIAM L. HALL, GEORGE R. lVILKINs. 

